The Living World — BIOLOGY STD 11 Science — Question

Explain the difference between Oxidative Phosphorylation and Photophosphorylation.

Briefly describe the following:
Heart failure.

Biology teacher was teaching cell cycle in the class. She taught that cell is the basis from which life exists. Also explained well about cell cycle. Robin who was a bright student was facing difficulties in understanding the topic he reached home and asked her sister who is a student of biology in a college about details of cell cycle and cell theory. She explained him that according to cell theory, cells arise from pre-existing cells and the process involved is cell division. Sexually reproducing organisms start their life from a single cell, called zygote, and cell divisions do not stop with the formation of a mature organism, but continue throughout the life.

1. What is meant by cell cycle?
2. Which is the actual phase of cell division?
3. When (at what phase) do the cell organelles duplicate?
4. What values are reflected from the Robin's concern?

(i) Renin hormone is secreted by which cells? Write one function of it.
(ii) Make a labelled diagram of the longitudinal section of the kidney.

Tell the main symptoms of Viroid.

Each plant or group of plants have some phylogenetic significance in relation to evolution: Cycas, one of the few living members of gymnosperms is called as the 'relic of past'. Can you establish a phylogenetic relationship to Cycas with any other group of plants that justifies the above statement?

Give the location of hepatic caecae in a cockroach. What is their function?

Name the internal/plant factors that determine the rate of photosynthesis.

Label the following structures labelled as A-F in the diagram.